It seems (and I think that this has come up before over the years) that adjusting the pH of juice MAY introduce some instability of the juice is subject to cool temperatures. I don't know at this point if this only happens with juice that has been used but I suspect it may be true of unopened juice.
I just checked a dipping container that has been outside on our porch for the past month. It contained diluted eGoo that I used in a session on Oct. 11. There was white sediment. The juice still bubbled reasonably but the pH had fallen to 7.0 from the 7.6 that it started with. I added about 1/2 tsp baking soda per liter juice to bring the pH back up to 7.3 or so.
That container had been outside for a month with temperatures dropping to 40F on a few nights. An unopened container of diluted eGoo that was diluted on the same date and adjusted to 7.52 still measures 7.52 and has no sediment. It is (as expected) slightly cloudy. It has been stored indoors where the temperature has not fallen below 63F.
It has been mentioned over the years that when the temperature drops some juice shows signs of a white precipitate.
More study needs to be done. The following tests would be worthwhile.
- Mix up a 20:1 distilled water:detergent base with added PEO.
- From this base, create two portions whose pH has been adjusted to 8.4 with citric acid
- From base, create two portions whose pH has been adjusted with baking soda to pH 8.4
- From base, create two portions whose pH has been adjusted to 7.6 with citric acid
- Create two portions of the base
Store one portion of each solution indoors so that the temperature does not drop below 65F
Store one portion of each solution outdoors (or in a refrigerator).
Observe visible changes over the course of a month.
2015 Feb Update
Some experiments (that I have yet to post due to limited time) done in February 2015 have demonstrated that when pH-adjusted bubble juice that has been exposed to cold temperatures for long enough precipitate forms that may result in a slight pH rise. It is unknown what the trigger temperature is. It is less than 63F and above 40F.
Experimental Summary. Several solutions were mixed at 20:1 (water to Dawn Pro dilution ratio). PH of some solutions was adjusted down to 7.7 using citric acid. Refrigerated solutions with citric acid developed a white precipitate after several hours. The pH was slightly elevated. Once the temperature was back at room tempertature, the bottle was shaken; the precipitate re-dissolved. Precipitate did no form in a simple detergent/water solution or with a detergent/water/BLM solution. The solution with precipitate worked fine.